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18
4
Strategies
Don L. Ivey and Charles V. Zegeer
The primary objective addressed by strategy is to maximize the beneï¬t to society forevery action and expenditure taken by state departments of transportation (DOTs),local highway agencies (HAs), and utility companies (utilities) in a collision reduc-
tion program. A secondary but important objective is to institute a program that will pro-
vide state DOTs, local HAs, and utilities with the best defensive position relative to
potential litigation. Strategies and analytical methods to maximize these beneï¬ts have
been developed and used by some state DOTs and a few utilities and municipalities with
good results (see Chapter 5). Examples of these are the approaches of Zegeer and Parker
(1), that of Grifï¬n et al. (2), and the method presented in the current AASHTO Roadside
Design Guide (RDG) (3).
Each of these approaches has advantages. The Zegeer approach relies on only three fac-
tors: trafï¬c count, lateral distance to poles, and pole density to predict accident frequency.
It is statistically derived but admittedly has limited predictive power. The Grifï¬n approach
is potentially more powerful statistically but is somewhat more complicated to apply.
The RDG is a beneï¬tâcost approach, used most commonly to evaluate the potential dan-
ger of roadside objects and how that compares with the application of guardrails or crash
cushions.
The authors have not been insulated from the ï¬eld of litigation and have developed a
clear understanding of the strategies of both the plaintiff and the defendant over the past
three decades.
As part of these analyses and efforts to achieve an optimum approach, every effort has
been made to ï¬nd and take advantage of the strengths of various approaches while
respecting the justiï¬able objectives and economic constraints of utility companies. In so
doing, the following objectives were considered:
1. Prevent the recurrence of a fatality or injury at sites where collisions have already
occurred.
2. Prevent the occurrence of a fatality or injury at sites where collisions are likely to
occur.
3. Save the utility maintenance funds.
4. Put a utility in the best position to defend the clearly random collision. (This is poten-
tially a way to save the stockholders and customers of a utility millions of dollars.)
Don L. Ivey, Texas Transportation Institute, College Station, TX 77843. Charles V. Zegeer, North Carolina Highway
Safety Research Center, Bolin Creek Center, 730 Airport Road CB-3430, Chapel Hill, NC 27599-3430.

Perhaps the term âclearly random collision or eventâ is not familiar. It is this event and
the ability to deï¬ne it that will provide a utility, local HA, or state DOT the best legal
defense against litigation. One way of deï¬ning the clearly random event is that it is
everything outside the realm of the predictable. Predictive equations have been devel-
oped that are strong enough to make cost-effective site selections. If utilities, local HAs,
and state DOTs act in an appropriate way in prioritizing and treating the predictable,
then a strong defense can be laid not only against the clearly random but also against the
lower-priority levels of the predictable. The result is the following three-path approach:
best offense, best bet, and best defense (4).
BEST OFFENSE
This is the most obvious of the approaches and historically the most frequently used,
residing firmly in the realm of common sense. It is improving safety where an atypical
number of collisions have already occurred. It will work toward Objective 1, prevent-
ing the recurrence of a fatality or injury at sites where multiple collisions have already
occurred. What is required is for a utility to know where collisions are occurring. There
are two practical approaches. The first and most direct is to make arrangements with
the appropriate law enforcement agency or agencies to secure copies of all collisions
involving a part of the utilityâs physical plant (e.g., utility poles). Those collisions are
then located to determine the facility sustaining the damage. Usually at least 3 years of
accident data are necessary to begin determining the most susceptible sites, but some-
times a congregation of crosses placed by survivors or other observations in the field
can be clues hard to misinterpret. The identified locations of a pole or poles atypically
exposed can then be prioritized for movement or treatment. This is the most immedi-
ately visible and most obviously effective portion of the safety program. Such a pro-
gram was designed by Mak (5) and successfully applied by Jacksonville Electric
Authority in 1989. However, this approach suffers from requiring unsupportably costly
collisions for definition (i.e., it is reactive instead of proactive). It is a part of the pro-
gram that should take priority early and gradually be reduced in importance as these
obvious exposed areas are changed. Note that this approach will also help accomplish
Objectives 2, 3, and 4.
BEST BET
In this phase of the program, pole lines and roadways are prioritized by statistical algo-
rithms that can be applied before an accident history develops. Zegeer and Parker have
developed prediction equations and data useful in prioritizing pole lines of signiï¬cant
length. Good et al. (6) have also developed useful relationships. These relatively simple
equations rely on trafï¬c volume, pole offset, and pole spacing to predict where the prob-
ability of pole collisions is greatest.
They are based on a comprehensive database from 1,534 roadway sections covering
25,193 roadway miles. The sections are in Michigan, North Carolina, Washington, and
Colorado. Six to 10 years of accident data were required for each section. The analysis
included more than 9,600 utility pole accidents.
A major accomplishment was the development of a regression model (7) to predict
utility pole accidents:
where
Accidents/mi/yr = number of predicted utility pole accidents per mile,
ADT = annual average daily trafï¬c volume,
Accidents/mi/yr (ADT) +
3.54 10 density
offset
= Ã
Ã
â
â
â
9 84 10 0 045
2
0 6.
( )
( )
..
Strategies 19

density = number of utility poles per mile within 30 ft (10 m) of the roadway,
and
offset = average lateral offset of the utility pole from the roadway edge on
the section.
Because pole collisions are generally low-probability events, the power of these algo-
rithms to make accurate predictions is limited. Thus, this prioritization scheme should
probably be only one of the controlling factors dictating change. It might be especially help-
ful in concert with right-of-way expansions or roadway widening (i.e., DOT improvement
projects). For example, if a DOT project allowed movement of a pole line from 10 ft behind
the curb to 18 ft, there is a good probability the money for utility movement would be bet-
ter spent elsewhere. Thus, a utility could propose, on the basis of statistical probability, that
a higher-priority section of poles be moved or treated with the funds that would have been
expended on the 10-ft to 18-ft project (e.g., where poles could be moved from 2 ft to 10 ft).
Further, when a given pole line shows a high priority for change, that occasionally could
be used by a DOT to justify the acquisition of more right-of-way. Note that this best bet
approach will apply directly to Objective 2 and will help accomplish Objectives 3 and 4.
Finally, something else should be accomplished while saving lives and limbs. Safety
funds should not be dissipated on frivolous lawsuits. The ï¬nal approach will be likely to
prove a great frustration to plaintiff attorneys with unjustiï¬able lawsuits.
BEST DEFENSE
In the courthouse, a second legally damaging condition for a pole line, right behind a sig-
niï¬cant accident history, is failure to meet the recommendations of the RDG (3). This is
already true for state DOTs, counties, and cities. It is likely to become true for utilities as
the aforementioned governmental entities take the logical steps to share the responsibil-
ity for roadside safety. This has been true even in cases in which the degree to which non-
compliance with the RDG recommendations is slight. In Arizona, the city of Mesa was
recently held accountable for a drainage structure 15 ft from the traveled way, while the
RDG recommended 17.5 ft. A way of decreasing the liability for letter-of-the-law diver-
gences from RDG recommendations is as follows:
1. Document the areas, pole lines, and individual poles that were originally placed or
came to be placed in conï¬ict with the clear zone recommendations of the RDG.
2. Use the physical characteristics of these sites to calculate the percent compliance (PC)
value with the RDG. Interpret the PC value to secure a priority number (PN). Note the
relationship between PN and PC with the RDG can be derived to achieve the most
productive priority listing by using lateral encroachment predictions and relative risk
relationships.
3. Schedule modiï¬cation of sites according to the PNs.
4. Perform safety treatment of a reasonable number of the highest-priority sites each
year. (Some utilities have found a cost-beneï¬cial investment of $100,000 per year will
yield effective progress.)
In this way, if an area is in reasonable compliance with the RDG clear zone (e.g., there
is a 15-ft clear zone instead of the recommended 17.5 ft), it will show up as a very low
priority for treatment and thus place the state DOT, the local HA, and the utility in a good
defensive position if one of these sites is subject to the rare and unpredictable random
collision. Note that this third strategy pursued in concert with the ï¬rst two will clearly
accomplish Objective 4.
The following is a simpliï¬ed approach that was recently implemented by Lafayette
Utilities System (see Chapter 5 for more detailed information).
Step 1. Continue to monitor collisions with utility structures to determine whether sites
are disposed to repeated collisions or are simply subject to the purely random
collision that is unlikely to be repeated.
20 Utilities and Roadside Safety

TRB State of the Art Report 9: Utilities and Roadside Safety includes the latest information on utility company, state department of transportation (DOT), and local highway agency roadside safety programs; describes the current status of a combined federal and industry effort to implement roadside safety, including yielding poles; and documents recent developments in guardrail, concrete barrier, and crash cushion design to reduce utility maintenance costs, potential liability, and public health costs.

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